30515. (a) Notwithstanding Section 30510, "assault weapon" also
means any of the following:
...
(4) A semiautomatic pistol that has the capacity to accept a
detachable magazine and any one of the following:
(A) A threaded barrel, capable of accepting a flash suppressor,
forward handgrip, or silencer.

If one can get department authorization for an 'assault weapon', LEO can buy one.